BACKGROUND The physiological response to hemorrhage includes vasoconstriction in an
effort to shunt blood to the heart and brain. Hemorrhaging patients can be classified as …

Background Hemorrhagic shock produces an immediate activation of the autonomic
nervous system and endogenous opioid pathways. Our studies have demonstrated that …

Interventions The rats were implanted with a femoral catheter and subcutaneous electrodes
for electrocardiogram recording and were randomly assigned to receive morphine (5 mg/kg) …

Potential health benefits of an acute fast include reductions in blood pressure and increases
in vagal cardiac control. These purported health benefits could put fasted humans at risk for …

BACKGROUND: The haemodynamic response to progressive hypovolaemia, whether
simulated by lower body negative pressure (LBNP) or head-up tilt, or induced by …

Background We have shown previously that hemorrhagic hypotension is associated with a
progressive development of vascular hyporeactivity to norepinephrine (NE). The present …

Introduction Haemorrhage is associated with changes in the cardiac autonomic drive which
begins during early stages of mild haemorrhage. The knowledge of chronology of the …

Background Intrathecal administration of morphine produces intense analgesia, but it
depresses respiration, an effect that can be life-threatening. Whether intrathecal morphine …

The mechanism of vasovagal syncope during orthostasis in humans is unknown. Opioid
receptors have been implicated in the vasovagal-like responses to hemorrhagic …

Background Haemorrhagic hypotension is accompanied by an increase in endogenous
opioid system activity, however, its significance is not fully recognised. Therefore, the role of …